Templeton-Cambridge Journalism Fellowships in Science & Religion

Atheism is unknown there; Infidelity rare and secret; so that persons may live to a great Age in that Country, without having their Piety shocked by meeting with either an Atheist or an Infidel.

Little seems to have changed since Benjamin Franklin penned those words of advice to would-be immigrants in 1782. Most polling data suggest that some 90 percent of Americans believe in God or a supreme spirit. And a recent University of Minnesota study finds that atheists—or at least that lonely 1 percent of the national mix that dares to identify itself as such—are the least trusted group in America.

A mind is a tough thing to think about. Consciousness is the defining feature of the human species. But is it possible that it is also no more than an extravagant biological add-on, something not really essential to our survival? That intriguing possibility plays on my mind as I cross the plaza of the Salk Institute for Biological Studies, a breathtaking temple of science perched on a high bluff overlooking the Pacific Ocean in La Jolla, Calif. I have just visited the office of Terry Sejnowski, the director of Salk’s Computational Neurobiology Laboratory, whose recent research suggests that our conscious minds play less of a role in making decisions than many people have long assumed. The dopamine neurons are responsible for telling the rest of the brain what stimuli to pay attention to, Sejnowski says, referring to the cluster of brain cells that produce one of the many chemical elixirs that activate, deactivate, or otherwise alter our mental state. In a deeper way, he explains, evolutionary factors—the need for individual organisms to survive, find food or a mate, and avoid predators—are at work behind the mechanisms of unconscious decision making. Consciousness explains things that have already been decided for you, Sejnowski says. Asked whether that means that consciousness is only a bit player in the overarching drama of our lives, he admits that it’s hard to separate rationalizing from decision making. But, he adds, we might overrate the role of our consciousness in making decisions.

Will the sum and substance of that evanescent phenomenon we call mind one day be completely understood in terms of the physical structure and functioning of the brain? Some philosophers and scientists think so. They believe that even the deepest puzzlements of the human psyche—awareness, the sense of self, and consciousness itself—will yield to the scientific investigations of neuronal circuitry and chemistry. Thanks to a host of new and ever-improving brain-monitoring and imaging technologies, we will come to see not only how brain architecture and activity correlate with consciousness but how they cause it—and even, if we agree with the philosopher Daniel Dennett, how they are it. If successful, this dazzling feat of reductionism will close the Cartesian mind-body divide and bring the intractable mind fully into the Darwinian paradigm, making the seat of the soul no less a mystery than any other highly evolved product of natural selection.